Determination system and method for dust pollution loss of photovoltaic module

Abstract

The invention relates to the technical field of photovoltaic dust deposition evaluation, in particular to a photovoltaic module dust deposition pollution loss measuring system and method. The actual dust accumulation environment is simulated through the test glass plate, and the irradiance values above and below the test glass plate are synchronously obtained through the first irradiation meter and the second irradiation meter; the irradiance values above and below the test reference glass plate are synchronously obtained through a third irradiatometer and a fourth irradiatometer, and interference of ambient light fluctuation on light transmittance calculation is effectively eliminated in combination with a background irradiance value measured in a shading state; by comparing the light transmittance difference between the test glass plate and the reference glass plate, the optical transmission loss caused by the dust pollution is directly separated, and the accurate evaluation of the dust pollution of the photovoltaic module is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic dust accumulation evaluation, and particularly relates to a system and method for measuring the dust accumulation pollution loss of photovoltaic modules. Background Art

[0002] With the rapid development and large-scale application of photovoltaic power generation technology, the installed capacity of global photovoltaic power stations has been continuously climbing. However, photovoltaic modules are long-term exposed to the natural environment, and their surfaces are extremely prone to accumulate pollutants such as dust, sand, bird droppings, and leaves. These pollutants will form a shielding layer on the surface of the module, reducing the light transmittance of the glass cover plate, thereby hindering the absorption of light energy and resulting in a significant decrease in the photoelectric conversion efficiency.

[0003] Research shows that in arid and semi-arid regions with strong winds and little precipitation, where photovoltaic resources are abundant, the problem of dust accumulation pollution is particularly prominent. Severe dust accumulation can reduce the power generation efficiency of photovoltaic modules by 20% - 25%, and even up to more than 30% in extreme cases. In addition, uneven dust accumulation may also trigger the hot spot effect, accelerating the aging of the module and further shortening its service life. This efficiency loss not only directly affects the power generation revenue of the power station, but also increases the operation and maintenance costs and reduces the return on investment. Therefore, establishing an accurate monitoring and evaluation system for photovoltaic module dust accumulation pollution and formulating a scientific cleaning strategy based on this are of great significance for improving the operation efficiency of photovoltaic power stations and ensuring economic benefits.

[0004] Currently, photovoltaic power stations usually use the following methods to evaluate the dust accumulation pollution loss: (1) Visual inspection method: By manually observing the dust accumulation on the surface of photovoltaic modules to subjectively judge the pollution degree. This method highly depends on the experience of operation and maintenance personnel and lacks a unified quantitative standard, resulting in low accuracy of the evaluation results. In addition, photovoltaic power stations are usually large in scale and have a large number of modules. Manual inspection is inefficient and difficult to achieve comprehensive and high-frequency monitoring, unable to meet the needs of refined operation and maintenance.

[0005] (2) Inverter power generation comparison method: By comparing the output power changes of inverters at different times to infer the impact of dust accumulation pollution. However, the power generation performance of the photovoltaic system is not only affected by dust accumulation, but also interfered by factors such as component aging, hot spot effect, and weather changes. Historical data is difficult to fully match the current working conditions, resulting in large errors in the evaluation results. In addition, this method usually relies on long-term data accumulation and is difficult to achieve real-time monitoring, unable to provide timely basis for operation and maintenance decisions.

[0006] (3) Historical data comparison method: Estimating the dust accumulation loss based on historical power generation data, but it also cannot exclude the interference of factors such as environmental conditions and equipment aging, resulting in large errors in the evaluation results.

[0007] The above methods all have the problems of rough measurement and insufficient accuracy, and it is difficult to achieve rapid and accurate determination of the loss caused by dust pollution. Therefore, there is an urgent need for a system and method that can evaluate the loss caused by dust pollution on photovoltaic modules in real time and accurately, provide a scientific basis for the operation and maintenance management of photovoltaic power stations, thereby improving power generation efficiency and reducing cleaning and maintenance costs. Summary of the Invention

[0008] The purpose of the present invention is to solve the problems in the prior art and provide a system and method for determining the loss caused by dust pollution on photovoltaic modules, which can evaluate the dust pollution on photovoltaic modules in real time and accurately.

[0009] To achieve the above object, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a method for determining the loss caused by dust pollution on photovoltaic modules, including the following steps: Obtain the irradiance above the test glass plate through a first irradiance meter and obtain the irradiance below the test glass plate through a second irradiance meter ; obtain the irradiance above the reference glass plate through a third irradiance meter ; obtain the irradiance below the reference glass plate through a fourth irradiance meter ; Cover the test glass plate with a test glass plate light-shielding cover, and obtain the irradiance below the test glass plate at this time through the second irradiance meter ; cover the reference glass plate with a reference glass plate light-shielding cover, and obtain the irradiance below the reference glass plate at this time through the fourth irradiance meter ; The specific calculation formula for the loss caused by dust pollution is:

[0010] where is the dust pollution loss rate.

[0011] Preferably, the reference glass plate needs to be cleaned before the test to make its surface dust-free.

[0012] Preferably, the test glass plate, the reference glass plate and the photovoltaic modules in the area of the photovoltaic power station to be measured are all in the same dust accumulation environmental conditions.

[0013] Preferably, the irradiance meter is calibrated before the test.

[0014] In the second aspect, the present invention provides a system for determining the loss caused by dust pollution on photovoltaic modules, including: A test glass plate, with a first irradiance meter arranged above the test glass plate; a second irradiance meter arranged below the test glass plate; A reference glass plate, with a third irradiance meter arranged above the reference glass plate; a fourth irradiance meter arranged below the reference glass plate; A light-shielding cover for the test glass plate, used to cover the test glass plate; A light-shielding cover for the reference glass plate, used to cover the reference glass plate.

[0015] Preferably, the installation angles of both the test glass plate and the reference glass plate are the same as the installation angle of the photovoltaic modules in the area of the photovoltaic power station to be measured.

[0016] Preferably, the materials of both the test glass plate and the reference glass plate are the same as the materials of the photovoltaic modules in the area of the photovoltaic power station to be measured.

[0017] Preferably, the first irradiance meter and the second irradiance meter are 10 - 20 cm away from the surface of the test glass plate.

[0018] Preferably, the third irradiance meter and the fourth irradiance meter are 10 - 20 cm away from the surface of the reference glass plate.

[0019] Preferably, it includes a data processing unit, and all the irradiance meters are connected to the data processing unit.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The present invention simulates the actual dust accumulation environment through the test glass plate, and synchronously obtains the irradiance values above and below the test glass plate through the first irradiance meter and the second irradiance meter; synchronously obtains the irradiance values above and below the reference test glass plate through the third irradiance meter and the fourth irradiance meter, and combines the background irradiance value measured under the light-shielded state to effectively eliminate the interference of environmental light fluctuations on the transmittance calculation; by comparing the transmittance differences between the test glass plate and the reference glass plate, directly separates the optical transmission loss caused by dust pollution, and realizes the accurate evaluation of the dust pollution of photovoltaic modules. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is a schematic diagram of a system for measuring the dust pollution loss of a photovoltaic module of the present invention.

[0023] Among them: 1. Test glass plate; 2. Reference glass plate; 3. First irradiance meter; 4. Second irradiance meter; 5. Third irradiance meter; 6. Fourth irradiance meter; 7. Light-shielding cover for the test glass plate; 8. Light-shielding cover for the reference glass plate. Detailed implementation manners

[0024] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not require further definition and explanation in subsequent drawings.

[0027] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, or the orientations or positional relationships in which the inventive product is customarily placed during use, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, terms such as "first", "second", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0028] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0029] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "connected" are understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0030] The present invention will be further described in detail below with reference to the accompanying drawings: The first object of the present invention is to provide a method for measuring the loss of photovoltaic module due to dust accumulation pollution, including the following steps: Obtain the irradiance above the test glass plate 1 through the first irradiance meter 3 and obtain the irradiance below the test glass plate 1 through the second irradiance meter 4 ; obtain the irradiance above the reference glass plate 2 through the third irradiance meter 5 ; obtain the irradiance below the reference glass plate 2 through the fourth irradiance meter 6 ; Cover the test glass plate hood 7 on the test glass plate 1, and obtain the irradiance below the test glass plate 1 at this time through the second irradiance meter 4; cover the reference glass plate hood 8 on the reference glass plate 2, and obtain the irradiance below the reference glass plate 2 at this time through the fourth irradiance meter 6; The specific calculation formula for the loss of dust accumulation pollution is:

[0031] wherein, is the dust accumulation pollution loss rate.

[0032] The present invention can accurately quantify the dynamic impact of dust accumulation pollution on the transmittance by synchronously collecting the irradiance data above and below the test glass plate 1 and the reference glass plate 2, and combining the interference measurement of blocking the incident light by the light-shielding cover. Specifically, the test glass plate 1 simulates the actual dust accumulation environment, and the irradiance values above and below it are synchronously obtained through the first irradiance meter 3 and the second irradiance meter 4, and combined with the background irradiance value measured in the light-shielded state, effectively eliminating the interference of environmental light fluctuations on the transmittance calculation; the reference glass plate 2 provides a reference transmittance in the dust-free state, and by comparing the transmittance differences between the test glass plate 1 and the reference glass plate 2, the optical transmission loss caused by dust accumulation pollution is directly separated, and finally the dust accumulation pollution loss rate is obtained.

[0033] The reference glass plate 2 needs to be cleaned before the test to make its surface dust-free, which improves the scientificity and accuracy of the measurement of the loss of dust accumulation pollution. The reference glass plate 2, as a reference object, its dust-free state can provide standardized transmittance data, and by comparing with the transmittance of the test glass plate 1, the interference of environmental factors (such as irradiance fluctuations, equipment attenuation) on the measurement results can be accurately stripped.

[0034] The test glass plate 1, the reference glass plate 2 and the photovoltaic modules in the area of the photovoltaic power station to be measured are all in the same dust accumulation environment conditions. The consistency of the dust accumulation environment conditions can accurately simulate the dust deposition process of photovoltaic modules during actual operation, including key factors such as dust type, deposition rate, wind force effect and temperature and humidity influence, thus avoiding measurement deviation caused by environmental variable differences.

[0035] The irradiometer is calibrated before testing. The calibration method is to compare the irradiometer reading with the standard value under a standard light source, so that the measurement error ≤ 1%, ensuring the accuracy and reliability of the measurement data.

[0036] The second object of the present invention is to provide a system for measuring the dust pollution loss of a photovoltaic module. The dust pollution loss measurement system is arranged in the area of the photovoltaic power station to be measured, such as Figure 1 as shown, including: A test glass plate 1, with a first irradiometer 3 arranged above the test glass plate 1; a second irradiometer 4 is arranged below the test glass plate 1; through the first irradiometer 3 and the second irradiometer 4 arranged above and below the test glass plate 1, the irradiance data of the incident light and the transmitted light of the test glass plate 1 can be synchronously obtained, dynamically monitoring the attenuation effect of dust on the light transmittance, providing raw data support for the calculation of pollution loss, and ensuring that the measurement results are highly consistent with the actual working conditions.

[0037] A reference glass plate 2, with a third irradiometer 5 arranged above the reference glass plate 2; a fourth irradiometer 6 is arranged below the reference glass plate 2; the third irradiometer 5 and the fourth irradiometer 6 above and below the reference glass plate 2 can provide standard light transmittance data. By comparing with the light transmittance of the test glass plate 1, interference factors such as environmental fluctuations and equipment errors can be accurately stripped, directly quantifying the optical loss caused by dust pollution, and significantly improving the credibility of the calculation results.

[0038] A test glass plate light-shielding cover 7, used to cover the test glass plate 1; a reference glass plate light-shielding cover 8, used to cover the reference glass plate 2. The light-shielding cover blocks the incident light by completely covering the glass plate, accurately measuring the intensity of background stray light (such as ground reflected light, atmospheric scattered light, etc.), so as to deduct the interference of stray light in the light transmittance calculation, and effectively avoiding the problem of falsely high light transmittance caused by ignoring background noise in the traditional method, making the calculation result of the dust pollution loss rate closer to the true optical loss and improving the evaluation accuracy.

[0039] All the irradiometers described in the present invention adopt high-precision secondary standard irradiometers, and the spectral response range covers 300~1200nm, ensuring the accuracy of the full-band light intensity measurement, providing a stable and reliable data source for the calculation of the pollution loss rate, and meeting the requirements of refined monitoring.

[0040] The installation angles of the test glass plate 1 and the reference glass plate 2 are both the same as the installation angle of the photovoltaic modules in the area of the photovoltaic power station to be measured, ensuring that the dust deposition process fully simulates the actual operating environment. The unity of the installation angle can accurately reproduce the adhesion law of dust on the surface of the photovoltaic module (such as the sliding trend under the action of gravity and the distribution characteristics under the action of wind), avoiding the deviation of the dust coverage rate, thickness or distribution uniformity caused by the inclination difference.

[0041] The materials of the test glass plate 1 and the reference glass plate 2 are the same as those of the photovoltaic modules in the area of the photovoltaic power station to be measured, ensuring that the dust deposition patterns (such as dust adhesion density and distribution uniformity) of the test glass plate 1 and the reference glass plate 2 highly coincide with those of the actual photovoltaic modules, so as to truly reflect the influence of dust pollution on the light transmittance.

[0042] The first irradiance meter 3 and the second irradiance meter 4 are 10 - 20 cm away from the surface of the test glass plate 1; the third irradiance meter 5 and the fourth irradiance meter 6 are 10 - 20 cm away from the surface of the reference glass plate 2. On the one hand, it avoids the interference of local reflected light or thermal radiation on the irradiance meter from the glass plate surface when the distance is too close. On the other hand, it prevents the intrusion of ambient stray light (such as ground reflection and atmospheric scattering) into the measurement area when the distance is too far, resulting in data distortion.

[0043] The dust pollution loss measurement system of the present invention further includes a data processing unit. The irradiance meters are all connected to the data processing unit, and the data processing unit is used to receive the irradiance data in real time and automatically calculate the dust pollution loss rate.

[0044] Example 1 1) The photovoltaic module dust pollution loss measurement system is arranged in the area of the photovoltaic power station to be measured. The test glass plate 1 and the reference glass plate 2 have the same installation angle and environment as the photovoltaic power station modules. The test glass plate 1 accumulates dust under the same natural environment as the photovoltaic power station modules, and the reference glass plate 2 is manually cleaned to be free of dust before the test.

[0045] 2) When measuring the dust pollution loss, record the readings of the first irradiance meter 3 above the test glass plate 1 as 900 W / m 2 , the readings of the second irradiance meter 4 below the test glass plate 2 as 720 W / m 2 , the readings of the third irradiance meter 5 above the reference glass plate 2 as 900 W / m 2 , and the readings of the fourth irradiance meter 6 below the reference glass plate 2 as 855 W / m 2 .

[0046] 3) Cover the test glass plate light-shielding cover 7 and the reference glass plate light-shielding cover 8 on the test glass plate 1 and the reference glass plate 2 respectively to block the front of the glass plates, and record the readings of the second irradiance meter 4 below the test glass plate 1 as 80 W / m 2 , and the readings of the fourth irradiance meter 6 below the reference glass plate 2 as 82 W / m 2 , which is the background irradiance.

[0047] 4) Remove the light-shielding cover 7 of the test glass plate and the light-shielding cover 8 of the reference glass plate, and the test is completed.

[0048] 5) Calculate the relative light transmittance of the test glass plate 1 under the dust deposition condition, obtain the optical transmission loss caused by the pollutants, and finally obtain the dust deposition pollution loss.

[0049] The calculation formula is:

[0050] The calculated dust deposition pollution loss γ is 17.2%.

[0051] Example 2 1) The dust deposition pollution loss measurement system of the photovoltaic module is arranged in the area of the photovoltaic power station to be tested. The installation angles and environments of the test glass plate 1, the reference glass plate 2 and the photovoltaic power station modules are the same. The test glass plate 1 and the photovoltaic power station modules are dust-deposited in the same natural environment, and the reference glass plate 2 is manually cleaned to be dust-free before the test.

[0052] 2) When measuring the dust deposition pollution loss, record the readings of the first irradiance meter 3 above the test glass plate 1 as 820 W / m 2 , the readings of the second irradiance meter 4 below the test glass plate 2 as 630 W / m 2 , the readings of the third irradiance meter 5 above the reference glass plate 2 as 820 W / m 2 , and the readings of the fourth irradiance meter 6 below the reference glass plate 2 as 780 W / m 2 .

[0053] 3) Cover the light-shielding cover 7 of the test glass plate and the light-shielding cover 8 of the reference glass plate on the test glass plate 1 and the reference glass plate 2 respectively to block the front of the glass plates, and record the readings of the second irradiance meter 4 below the test glass plate 1 as 80 W / m 2 , and the readings of the fourth irradiance meter 6 below the reference glass plate 2 as 85 W / m 2 , which is the background irradiance.

[0054] 4) Remove the light-shielding cover 7 of the test glass plate and the light-shielding cover 8 of the reference glass plate, and the test is completed.

[0055] 5) Calculate the relative light transmittance of the test glass plate 1 under the dust deposition condition, obtain the optical transmission loss caused by the pollutants, and finally obtain the dust deposition pollution loss.

[0056] The calculation formula is:

[0057] The calculated dust pollution loss γ is 20.9%.

[0058] Example 3 1) The dust pollution loss measurement system for photovoltaic modules is arranged in the area of the photovoltaic power station to be measured. The test glass plate 1 and the reference glass plate 2 have the same installation angle and environment as the photovoltaic power station modules. The test glass plate 1 and the photovoltaic power station modules are dusted in the same natural environment, and the reference glass plate 2 is manually cleaned to no dust before the test.

[0059] 2) When measuring the dust pollution loss, record the readings of the first irradiance meter 3 above the test glass plate 1 as 880 W / m 2 and the readings of the second irradiance meter 4 below the test glass plate 2 as 705 W / m 2 and the readings of the third irradiance meter 5 above the reference glass plate 2 as 880 W / m 2 and the readings of the fourth irradiance meter 6 below the reference glass plate 2 as 790 W / m 2 .

[0060] 3) Cover the test glass plate light shield 7 and the reference glass plate light shield 8 on the test glass plate 1 and the reference glass plate 2 respectively to block the front of the glass plate, and record the readings of the second irradiance meter 4 below the test glass plate 1 at this time as 80 W / m 2 and the readings of the fourth irradiance meter 6 below the reference glass plate 2 as 83 W / m 2 , which is the background irradiance.

[0061] 4) Remove the test glass plate light shield 7 and the reference glass plate light shield 8, and the test is completed.

[0062] 5) Calculate the relative transmittance of the test glass plate 1 under dust conditions, obtain the optical transmission loss caused by pollutants, and finally obtain the dust pollution loss.

[0063] The calculation formula is:

[0064] The calculated dust pollution loss γ is 11.7%.

[0065] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for measuring the loss caused by dust accumulation pollution of a photovoltaic module, characterized in that, It includes the following steps: Obtain the irradiance above the test glass plate (1) through the first irradiance meter (3) , obtain the irradiance below the test glass plate (1) through the second irradiance meter (4) ; obtain the irradiance above the reference glass plate (2) through the third irradiance meter (5) ; obtain the irradiance below the reference glass plate (2) through the fourth irradiance meter (6) ; Cover the test glass plate light shield (7) on the test glass plate (1), and obtain the irradiance below the test glass plate (1) at this time through the second irradiance meter (4). Cover the reference glass plate light shield (8) on the reference glass plate (2), and obtain the irradiance below the reference glass plate (2) at this time through the fourth irradiance meter (6). ; The specific calculation formula for the loss caused by dust accumulation pollution is: Among them, is the dust accumulation pollution loss rate.

2. The method for measuring the loss caused by dust accumulation pollution of a photovoltaic module according to claim 1, wherein The reference glass plate (2) needs to be cleaned before the test to make its surface free of dust accumulation.

3. A method for measuring the loss caused by dust accumulation pollution of a photovoltaic module according to claim 1, wherein The test glass plate (1), the reference glass plate (2) and the photovoltaic modules in the area of the photovoltaic power station to be measured are all under the same dust accumulation environmental conditions.

4. The method for determining the loss caused by dust accumulation pollution of a photovoltaic module according to claim 1, characterized in that, The irradiance meter is calibrated before the test.

5. A photovoltaic module dust pollution loss measurement system, characterized in that, It includes: A test glass plate (1), with a first irradiance meter (3) arranged above the test glass plate (1); a second irradiance meter (4) arranged below the test glass plate (1); A reference glass plate (2), with a third irradiance meter (5) arranged above the reference glass plate (2); a fourth irradiance meter (6) arranged below the reference glass plate (2); A test glass plate light-shielding cover (7) for covering the test glass plate (1); A reference glass plate light-shielding cover (8) for covering the reference glass plate (2).

6. The dust accumulation pollution loss measurement system for a photovoltaic module according to claim 5, wherein The installation angles of the test glass plate (1) and the reference glass plate (2) are both the same as the installation angle of the photovoltaic modules in the area of the photovoltaic power station to be measured.

7. A photovoltaic module dust pollution loss measurement system according to claim 5, characterized in that The materials of the test glass plate (1) and the reference glass plate (2) are both the same as the materials of the photovoltaic modules in the area of the photovoltaic power station to be measured.

8. A photovoltaic module dust pollution loss measurement system according to claim 5, characterized in that, The first irradiance meter (3) and the second irradiance meter (4) are 10 - 20 cm away from the surface of the test glass plate (1).

9. A photovoltaic module dust pollution loss measurement system according to claim 5, characterized in that The third irradiance meter (5) and the fourth irradiance meter (6) are 10 - 20 cm away from the surface of the reference glass plate (2).

10. A photovoltaic module dust pollution loss measurement system according to claim 5, characterized in that, It includes a data processing unit, and the irradiance meters are all connected to the data processing unit.

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